public static function getLatestCommentByUserId($userId)
{
$status = new self();
$status->setProjection(array("comment"));
$status->setCondition("user_id", $userId);
$status->setOrderBy("created_at", "desc");
$status->setLimit(1);
$statuses = $status->select();
return isset($statuses[0]) ? $statuses[0]->comment : "";
}